I don't know about the free translators... sometimes i see websites that offer content in various languages, produced by google translate or something similar.
I suppose they are good to get started on a translation, but if you don't know the output language, you may end up making a total fool of yourself.
Then again, even major media make these mistakes. One of the leading newspapers in holland had a report about a bomb that was loaded with nuts and bolts (as shrapnell). The auto-translated that into 'noten en bouten', which does mean nuts and bolts, but nuts as in peanuts, not the ones that go onto bolts.
There are obviously worse examples, resulting in obscenities i will not repeat here.